Apparatus for interlacing multifilament yarn



July 26, 1966 w. c. SPARLING 3,262,179

APPARATUS FOR INTERLACING MULTI FILAMENT YARN Filed Dec. 1, 1964 2 Sheets-Sheet l INVENTOR WAYNE CLIFFORD SPARLIN G ATTORNEY APPARATUS FOR INTERLACING MULTI-FILAMENT YARN Filed Dec 1, 1964 2 Sheets-Sheet 2 INVENTOR WAYNE CLIFFORD SPARLIN 6 ATTORNEY United States Patent 3,262,179 APPARATUS FQR INTERLACING MULTL FILAMENT YARN Wayne Clifford Sparling, Newark, DeL, assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Dec. 1, 1964, Ser. No. 414,974 1 Claim. (Cl. 28-1) This invention relates to apparatus for treating yarn and is particularly concerned with fluid jet apparatus suitable for interlacing as-spun or zero twist yarn in a continuous manner to produce a compact unitary structure.

Multifilament yarn producers had long sought a method which would obviate the need for twisting and/or slashing such yarn to insure adequate handling characteristics. As-spun or zero twist yarn performs poorly in many of the common textile operations, such as winding, weaving and knitting, due in the main to a looseness of structure which permits individual filaments to snag and break out, thence forming fluff balls, slubs, ringers, wraps, strip backs, or similar defects. Moreover, zero twist yarn runs in the form of a ribbon over guides, rollers, etc., and the attendant increase in friction often results in abraded yarn which is even more prone to mechanical failure. As a result of these shortcomings, the textile trade was extremely reluctant to use Zero twist yarn, and yarn producers had to carry out the additional step of twisting each yarn to provide the trade with an acceptable prod uct. Twisting, of course, serves to compact and unify a yarn bundle, resulting in a more cohesive structure which resists the pulling out of individual filaments. However, conventional true twisting is expensive and time-consuming and, being a relatively slow discontinuous operation, adds disproportionately to the cost of the yarn. Also, the mechanics of true twisting and the additional handling required often results in yarn of lower quality.

A great improvement over prior art practices has recently been provided by the inventions of Bunting and Nelson, US. Patents No. 2,985,995 granted May 30, 1961, and No. 3,110,151 granted November 12, 1963. In accordance with these patents, zero twist yarn can now be treated continuously at extremely high speeds to produce a yarn with handling and running characteristics equal to conventional twisted yarn. A compact interlaced yarn is obtained by passing a multifilament strand, under a positive tension, through a fluid jet which separates the filaments and groups of filaments from each other and then randomly intermingles them along the length of the yarn to maintain unity of the product by frictional constraint between the filaments. The interlace may either be periodic, having interlaced sections separated by noninterlaced sections, or continuous, in which a certain amount of intermingling exists at any cross-section along the yarn length. One type of fluid jet apparatus suited for the interlacing process is that of Bunting and Nelson US. Patent No. 3,115,691, granted December 31, 1963. With fluid-treating devices of this type, the interlacing action tends to accumulate randomly along the yarn. While the resulting yarn is compact and coherent, the periodic, tightly-interlaced ortions tend to introduce nonuniformities in the yarn during the course of subsequent yarn treatment such as weaving, texturing and the like.

An object of this invention is to provide an improved apparatus for treatment of a running multifilament yarn to produce a particularly uniform interlaced yarn.

In its preferred embodiment, the fluid interlacing apparatus of this invention comprises a body member having a yarn-treating face, two coplanar fluid conduits through the body member which terminate astride and communicating with a vortex cavity in the yarn-treating face, and positioned to direct two streams of high velocity fluid 3,262,179 Patented July 26, 1966 against a second opposing planar surface spaced apart from the face of the body member.

The present invention is illustrated by way of example in the accompanying drawings in which:

FIGURE 1 is an isometric view of a preferred embodiment of this invention,

FIGURE 2 is a vertical cross section taken through the fluid conduits as indicated in FIGURE 1,

FIGURE 3 is a front elevational detail of the body face indicated by line 33 in FIGURE 2, showing the arrangement of fluid conduits and configuration of cavity provided in the embodiment of FIGURE 1, and

FIGURE 4 through 9 are corresponding views of alternate arrangements of the fluid conduits and cavities within the scope of the present invention.

Referring to FIGURE 1, an isometric view of a preferred jet assembly is shown with yarn strand 18 in treating position. A body 10 contains two cylindrical fluid conduits 11 communicating with fluid manifold 12 which is supplied with fluid from any convenient source (not shown). The fluid conduits terminate in the yarn-treating face 13 of the body, along opposite edges of a vortex cavity 14. The fluid conduits 11 are positioned to direct fluid against the inner surface 15 of plate 16 which presents a wall spaced from the body to form yarn passageway 19. The spacing between the body face 13 and inner surface 15 of the plate may be adjusted to vary the yarn passageway 19 to accommodate various yarn deniers or desired fluid treating conditions, and is usually between about 0.008 and about 0.120 inch. Appropriate thread guides 1'7 direct the yarn along an axis passing between the axes of the fluid conduits 11 and over cavity 14. The axis of yarn 18 passing through passageway 19 is usually equidistant from the axes of the fluid conduits 11 FIGURE 2 shows in cross-section the relative positions of fluid conduits 11, vortex cavity 14 in body face 13, yarn filaments 20 and inner face 15 of plate 16. Faces 13 and 15 are preferably parallel planar surfaces. FIG- URE 3 is an elevational view of the face 13 of the body 10 showing the cavity 14 located between fluid conduits 11 and in alignment with the axis of yarn 18. In this preferred embodiment, the fluid conduits are circular in cross-section, of equal size, convergent and coplanar. However, other forms and arrangements are suitable, as illustrated in the additional figures. The diameter of the fluid conduits may range from about 0.020 to about 0.10 inch. The distance C between the axes of the fluid conduits at the face 13 of the body may vary from 0 to about 10 times the diameter of each fluid conduit, or the average conduit diameter when these conduit diameters are different. The optimum distance between conduits 1s approximately 2 to 3 times the conduit diameter.

A preferred fluid conduit arrangement, as illustrated above, is one in which the fluid conduits are angled with respect to each other. However, the conduits may be parallel to each other. The angle between the axis of the conduit and body face 13 may vary from 10 to The included angle between the axes of the conduits may vary from 0 (parallel) to The conduits may be angled either forward or backward with respect to the direction of strand travel so long as the axis of each conduit forms an acute angle of at least 10 with the planar surface of the body face 13.

As shown in FIGURES 2 and 3, vortex cavity 14 is recessed in body face 13 between the orifices of conduits 11. Referring to FIGURE 3, the cavity 14 has a width W measured in the plane of the body face 13 along a line which intersects the axes of a pair of fluid conduits 11. This Width W, at its maximum extent, will usually not exceed the greatest distance across a pair of fluid conduits 11 measured to the respective outside edges of each conduit. For example, in the plane of the body face 13, the boundary of the cavity 14 may be outside and generally tangential to the outer edge or outer periphery of the conduits 11. Conversely, the width W may be less than the smallest dimension between the inside edges of the fluid conduits such that the boundary of the cavity 14 falls short of intersecting the fluid conduits 11 by about 0.2 of the conduit diameter D on each side. For example, the width of the uninterrupted portion of the body face or land appearing between the boundary of the cavity 14 and the edge of one of the conduits 11 may be about 0.005 inch. If the dimension C in FIGURE 3 is used to designate the distance between the axes of the fluid conduits 11 measured in the plane of body face 13 then, from the foregoing, it will be seen that the width W should generally fall between the limits:

W maximum=C+D W minimum=C-1.4D

In the embodiment already described, the vortex cavity 14 will overlap or intersect the fluid conduits slightly as shown in FIGURE 3, in which the amount of the overlap on each side, measured in the plane of the body face 13, is about 0.1 of the conduit diameter D, or

For example, the overlap at each side may be about 0.005 inch. In this embodiment, the cavity is an elongated V-shaped groove of varying depth in which the included angle on shown in FIGURE 2 is about 90; the greatest depth of the cavity measured perpendicular to the body face 13 should be 2 to 3 times the spacing between the body face 13 and the plate face 15, while the distance C between the axes of the fluid conduits should be about 4 to times the spacing between body face 13 and wall surface 15.

Preferably the length of the cavity 14 is at least two times the width W, and the cavity 14 extends upstream of the direction of yarn travel from the conduits 11 at least 0.5 but not in excess of 1.5 times the width W. Downstream of the direction of yarn travel from the conduits 11, the length of the cavity 14 is relatively unimportant but will usually be about 1.0 to 2.5 times the Width W. The boundaries of the cavity should be entirely inside of the terminal edges of the body face 13, and preferably should fall short of any terminal edge by at least 0.05 inch.

The cavity may take other forms as shown in FIG- URES 4 through 9. FIGURES 4 and 5 illustrate a fluid interlacer with a cavity formed by two aligned continuous grooves, each similarly concave in form. Parallel fluid conduits are shown in this embodiment. FIGURES 6 and 7 show a triangular-shaped cavity of uniform depth. In the embodiment of FIGURES 8 and 9, the fluid conduits have flaring enlargements at the exists which merge to form a common cavity.

In preferred embodiments of the invention, each interlacing jet has a single pair of fluid conduits and each conduit is inclined toward the other. The cavity provides a chambered space within the apparatus for the filaments in the yarn bundle to move about and intermingle while under the influence of the plural vortices set up by the emerging fluid streams. Obviously a series of interlacing jets, having additional pairs of fluid conduits and appropriate communicating cavities, may be spaced along the thread path to provide plural treatment zones, and these may be combined in a single interlacing device, if desired.

In operating the apparatus of this invention, the interlacer is preferably positioned between suitable yarn forwarding and take-up means, i.e., means capable of ad vancing the strand through the interlacer at controlled positive tension. The tension can readily be adjusted to provide a compact interlaced product without texturing or bulking action. The overfeed (difference in surface speed between the feed and take-up rolls) will normally be substantially zero unless the yarn is simultaneously relaxed (shrunk), as by the use of heated fluid, in which case overfeeds of up to 20% may be used. While passing through the zone of controlled fluid turbulence formed by the two or more fluid vortices within the apparatus, the yarn bundle is opened (the filaments are separated) and the filaments are interlaced so that they become individually and collectively twisted, intertwined, and entangled in a random manner, thereby consolidating the yarn bundle to a compact unitary strand which maintains its unity even when the bundle is at zero twist. The strand is believed to maintain its unity solely due to frictional constraint between adjacent filaments and, of course, there is no need for adhesives or bonding or fusing of fibers in any way in order for the yarn to maintain its compact unity. The denier of the interlaced yarn thus produced may be substantially the same as the starting yarn and not substantially different from ordinary true twist yarn prepared from the same starting yarn, that is, a yarn having the same number of identical filaments with the same cross-sectional configuration.

Preferably, interlacing is carried out as an adjunct to one or more of the common textile operations such as spinning and/or drawing, packaging, etc., thereby taking advantage of existing suitable yarn forwarding means. The unity and compactness of the strands produced with this apparatus provide such a very suitable consolidated structure that the yarn may be handled as a unitary strand in the same manner as a true twist yarn conventionally utilized in textile operations. A detailed discussion of the process thereby is contained in Bunting and Nelson U.S. Patent No. 2,985,995, dated May 30, 1961. The apparatus of the present invention may be utilized in carrying out any of the procedures disclosed in that patent.

The fluid treating apparatus of this invention is an improvement over the apparatus indicated in FIGURE 14 of the above patent and disclosed in more detail in Bunting and Nelson U.S. Patent No. 3,115,691. The provision of a vortex cavity at the zone of impingement of the fluid upon the yarn provides better control of the yarn line within this zone and renders the apparatus more effective. The mechanism of the action within the cavity is not fully understood but the movement of the yarn through the treating zone is more stable. Higher fluid pressure may be used to provide a higher level of interlacing Without whipping the yarn bundle about and disrupting its passage through the device. The result is a highly uniform product. The filaments of the product are thoroughly intermingled and the yarn is coherent. At the same time, the product has a high degree of uniformity. The yarn has a particularly uniform bundle thickness with a minimum of tight and loose sections, and the filaments may be readily separated by hand without encountering tightly snarled and entangled filaments. The yarn is sufficiently cohesive to handle as a true twist yarn and yet the filaments are mobile within the yarn bundle. These qualities of the interlaced product lead, in turn, to improved performance in subsequent textile yarn processes such as warping, stulfer box crimping, falsetwist heat-set texturing, or fluid treatment.

Although not essential, guide means are preferred for directing the strand through the interlacer, preferably arranged so that the strand axis is perpendicular to a line joining the axes of the conduit pair on the interlacer face. However, the strand may lie anywhere within 20 of this position.

Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the specific illustrations except to the extent defined in the following claim.

I claim:

An apparatus for interlacing multifilament yarn, including in combination a body member having a yarn-treating face; a vortex cavity in said face; a well member having a planar surface spaced from said yarn-treating face to form a yarn passageway, yarn guide means for controlling the direction of yarn travel through said passageway; and a pair of fluid conduits through said body member and terminating at opposite sides of said vortex cavity in the yarn-treating face, on a line approximately at rightangles to the direction of yarn travel and positioned to direct fluid against said planar surface of the wall member; said vortex cavity having as the greatest depth a depth perpendicular to the yarn-treating face two to three times the spacing of said planar Wall surface from said face, and having the boundaries of the cavity entirely Within the edges of said face; the distance between the axes of said fluid conduits at said yarn treating face being about 4 to 10 times the spacing of said wall surface from said face.

References Cited by the Examiner UNITED STATES PATENTS ROBERT R. MACKEY, Primary Examiner. 

